NOTE: I HAVE A NUMBER OF POSTINGS I AM SENDING THAT DEAL WITH "MASSIVE OPEN ONLINE COURSES" [MOOCS] THAT ARE BEGINNING TO BE OFFERED. THEY WILL BRING THE READER UP TO DATE ON WHAT MOOCS ARE, THE MAJOR "PLAYERS," THE MAIN "PLATFORMS" AND THE IMPLICATIONS FOR EDUCATION. THESE WILL ARRIVE OVER THE NEXT SEVERAL DAYS ... JPB

Colleges and professors have rushed to try a new form of online teaching known as MOOC's-short for "massive open online courses." The courses raise questions about the future of teaching, the value of a degree, and the effect technology will have on how colleges operate. Struggling to make sense of it all? On this page you'll find highlights from The Chronicle's coverage of MOOC's.

What are MOOC's?

MOOC's are classes that are taught online to large numbers of students, with minimal involvement by professors. Typically, students watch short video lectures and complete assignments that are graded either by machines or by other students. That way a lone professor can support a class with hundreds of thousands of participants.

Why all the hype?

Advocates of MOOC's have big ambitions, and that makes some college leaders nervous. They're especially worried about having to compete with free courses from some of the world's most exclusive universities. Of course, we still don't know how much the courses will change the education landscape, and there are plenty of skeptics.

These are like OpenCourseWare projects, right?

Sort of. More than a decade ago, the Massachusetts Institute of Technology started a much-touted project called OpenCourseWare, to make all of its course materials available free online. But most of those are text-only: lecture notes and the like. Several colleges now offer a few free courses in this way, but they typically haven't offered assignments or any way for people who follow along to prove that they've mastered the concepts. MOOC's attempt to add those elements.

So if you take tests, do you get credit?

So far there aren't any colleges that offer credit for their MOOC's. But some MOOC participants can buy or receive certificates confirming their understanding of the material.

Who are the major players?

Several start-up companies are working with universities and professors to offer MOOC's. Meanwhile, some colleges are starting their own efforts, and some individual professors are offering their courses to the world. Right now four names are the ones to know:

edX

A nonprofit effort run jointly by MIT, Harvard, and Berkeley.

Leaders of the group say they intend to slowly add other university partners over time. edX plans to freely give away the software platform it is building to offer the free courses, so that anyone can use it to run MOOC's.

Coursera

A for-profit company founded by two computer-science professors from Stanford.

The company's model is to sign contracts with colleges that agree to use the platform to offer free courses and to get a percentage of any revenue. More than a dozen high-profile institutions, including Princeton and the U. of Virginia, have joined.

Udacity

Another for-profit company founded by a Stanford computer-science professor.

The company, which works with individual professors rather than institutions, has attracted a range of well-known scholars. Unlike other providers of MOOC's, it has said it will focus all of its courses on computer science and related fields.

Khan Academy

A non-profit organization founded by MIT and Harvard graduate Salman Khan.

Khan Academy began in 2006 as an online library of short instructional videos that Mr. Khan made for his cousins. The library-which has received financial backing from the Bill and Melinda Gates Foundation and Google, as well as from individuals-now hosts more than 3,000 videos on YouTube. Khan Academy does not provide content from universities, but it does offer automated practice exercises, and it recently debuted a curriculum of computer science courses. Much of the content is geared toward secondary-education students.

Udemy

A for-profit platform that lets anyone set up a course.

The company encourages its instructors to charge a small fee, with the revenue split between instructor and company. Authors themselves, more than a few of them with no academic affiliation, teach many of the courses.